Penile urethra

The penis consists of three components, two dorsolateral corpora cavernosa and a ventral corpus spongiosum that surrounds the penile urethra and distally forms the glans penis. The corpora cavernosa consist of blood-filled sinusoidal or lacunar spaces, which are lined with endothelial cells, supported by trabecular smooth muscle, and surrounded by a thick fibrous sheath called the tunica albuginea. The caver-nosal arteries, which are branches of the penile artery, penetrate the tunica albuginea and supply blood flow to the penis. 

The critical period for the induction of hypospadias by finasteride in rats is Days 16 to 17 of gestation (Clark et al., 1990a). It is unlikely that other agents would have a much earlier critical period since testosterone synthesis, which is required for the development of the penile urethra, begins in the rat on Day 15 of gestation (Habert and Picon, 1984). Thus, if treatment in the embryo-fetal development study... 

Figure 19.3 The lifetime journey of a spermatozoon. The journey of the spermatozoa starts in the seminiferous tubules of the male and finishes in the oviduct of the female. For ejaculation they must travel from storage in the epididymis and vas deferens to the penile urethra, a distance of about 20 cm. The distance travelled in the female reproductive system is also about 20 cm.

Lymphatics of the prepuce and penile shaft converge dorsally, and then drain into both right- and leftsided superficial inguinal lymph nodes via channels alongside superficial external pudendal vessels. Lymphatics of the glans and penile urethra pass deep to Buck s fascia and drain into both superficial and deep inguinal nodes. 

Because of its length, the male urethra is vulnerable to traumatic lesions that may cause acute urinary retention and sudden onset of urethrorrhagia and even late stenosis. Urethral trauma can be divided into external trauma, either contusive or penetrative, and internal or endourethral trauma. Internal traumas usually follow iatrogenic maneuvers. External traumas are frequent events and can occur in the penile urethra as a result of road or work accidents, sporting activities or sex. The urethra can be compressed by subcutaneous or intraspongiosal hematomas and may present complete or incomplete mucosal interruption. 

Fig. 19.10. Mucosal cyst of the penile urethra. Sonourethrography with sagittal scan. The cyst ( ) is anechoic with regular margin and protrudes into the urethral lumen distended with saline solution...

External genitalia XX various degree of genital ambiguity from clitoral enlargement to penile urethra) + + + +... 

Urethra, clitorial enlargment to penile urethra 558 Uric acid lithiasis 452, 453 Urinary tract infection 65, 303, 511, 512, 643 Urolithiasis 301, 303 Uropathy, obstructive 303, 454 Uterus, absent 562 Uvula, bifid 379... 

The penis has two corpora cavernosa, which have many interconnected sinuses that fiU with blood to produce an erection. The penis also has one corpus spongiosum, which surrounds the urethra and forms the glans penis. Acetylcholine works with other neurotransmitters (i.e., cyclic guanylate monophosphate, cyclic adenosine monophosphate, vasoactive intestinal polypeptide) to produce penile arterial vasodilation and ultimately an erection. Causes of organic ED include diseases that compromise vascular flow to the corpora cavernosum (e.g., peripheral vascular disease, arteriosclerosis, essential hypertension), impair nerve conduction to the brain (e.g., spinal cord injury, stroke), and are associated with hypogonadism (e.g., prostate or testicular cancer, hypothalamic or pituitary disorders). 

Passes a pus-like discharge per urethra and has penile sores. 

Priapism is a persistent erection of the corpora cavernosa of the penis, originating from disturbances to the mechanisms that control penile detumescence. This affects only the corpora cavernosa. The corpora spongiosum of the glans penis and surrounding the urethra are not part of the process. 

Patients with penile fracture may present with associated injury to the corpus spongiosum and to the anterior urethra. The severity of the lesions can be variable, ranging from urethral contusion to partial or complete rupture. 

Penile amputation is due to self-mutilation, assaults and accidents. About 200 cases have been reported in the literature. In penile amputation both the corpora cavernosa and corpus spongiosum with the urethra are involved (Aboseif et al. 1993), and the neurovascular dorsal bundle is dissected. Diagnosis is straightforward because the distal portion of the penile shaft... 

Roberts W (1872) A practical treatise on urinary and renal disease. Smith, Elder and Co, London Sanchez-Ortiz R, Huang SF, Tamboli P et al (2005) Melanoma of the penis, scrotum and male urethra a 40-year single institution experience. J Urol 173 1958-1965 Sanz Mayayo E, Burgos Revilla FJ, Gomez Garcia I et al (2004) [Penile metastasis of a prostatic adenocarcinoma]. Arch Esp Urol 57 841-844... 

The penile or pendulous urethra is of relatively uniform diameter, about 1 cm, stretching from the penile ligament to the external urethral meatus. Before its emergence at the meatus, there is an ampullar dilatation called the fossa navicularis. 

The anterior urethra can be explored using high frequency linear probes that are able to examine the penile and perineal tract and the structures of the surrounding corpus spongiosum (Gluck et al. 1988 Nash et al. 1995). This exam consists of scanning performed after a saline solution is introduced... 

Ultrasound examination identifies the urethrocele, located most often in the anterior urethra or the penile-scrotal ligament. The cavity appears as a single saccular image with clear edges and opens into the urethral lumen. Similar diverticular cavi-... 

Currently, the Cantwell-Ranswell urethroplasty is the method of choice (Kelly 1998 Ben-Chaim et al. 1996 Canning 1996 Husmann et al. 1993). Briefly, the urethra is tubularized over a catheter. The corporal bodies are freed completely from the glans and the proximal urethra, then rotated inward and sutured together. The procedure is finished by reconstruction of the glans and moving the distal end of the urethra to the ventral side of the penis. Penile ischemia can lead to an asymmetric appearance of the penis afterwards. 

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